The present invention relates to surgical scissors with two scissor blades mounted for pivotal movement relative to each other about a pivot axis and having one cutting edge each, the scissor blades having proximally of the pivot axis one sliding surface area each, the sliding surface areas sliding along each other and the scissor blades contacting each other distally of the pivot axis at a moving point of contact of the cutting edges sliding along each other when the scissors are opened and closed, and at least one of the cutting edges being provided with a hard material coating.
The present invention further relates to a method for the manufacture of surgical scissors with two scissor blades mounted for pivotal movement relative to each other about a pivot axis and having one cutting edge each, the scissor blades having proximally of the pivot axis one sliding surface area each, the sliding surface areas sliding along each other and the scissor blades contacting each other distally of the pivot axis at a moving point of contact of the cutting edges sliding along each other when the scissors are opened and closed, and at least one of the cutting edges being provided with a hard material coating.
A hard material coating within the meaning of this application is to be understood as a coating whose hardness is significantly increased in comparison with a base material forming the scissor blades. It is not to be understood as ceramic coating or coating applied by welding.
Surgical scissors of the kind described at the outset are used in order to increase a service life of the scissors in comparison with uncoated scissors. This is achieved, in particular, by at least one of the cutting edges being provided with a single-layer or multi-layer hard material coating, applied, for example, by chemical vapor deposition (CVD). In particular, titanium-nitride can be applied in a vacuum chamber by evaporating titanium in a nitrogen plasma. Of course, both cutting edges may also be provided with a hard material coating.
Furthermore, it is known that the scissor blades mounted on each other under initial tension contact each other at at least two points or areas when the scissors are opened and closed. These are, firstly, a moving point of contact of the cutting blades sliding along each other and, secondly, a point of contact or a contact surface of the sliding surface areas of the two scissor blades that slide along each other. The initial tension between the scissor blades required for the cutting can only be maintained on a long-term basis if not only wear at the cutting edges is minimized but also wear at the sliding surface areas that slide along each other.
The object of the present invention is, therefore, to so improve surgical scissors of the kind described at the outset that their service life is further increased.